Replacing a stack unit with stack interactive-setup

You must use stack interactive-setup to replace stack units in the following cases:

  • The replacement is not a clean unit.
  • You do not want the active controller to trigger an automatic replacement.
  • You are replacing multiple units simultaneously.

Note: If you are replacing more than one unit simultaneously, you may also use stack zero-touch provisioning to discover the units; however, stack interactive-setup allows interactive control of the process.
Note: If you use stack interactive-setup to assign a new unit an ID that has mismatched static configuration, the utility displays a warning message that the new unit will be put in a non-operational state after it joins the stack.
Note: You can return a configuration-mismatched unit to operation by configuring the no stack unit command for the nonoperational unit from the active controller. This removes the entire stack configuration so the active controller can learn the configuration-mismatched unit as a new unit. The active controller triggers an election and learns the unit. Refer to Recovering from a stack unit configuration mismatch for more information.

To replace a stack unit with stack interactive-setup, perform the following steps.

  1. (Optional) Enter the show stack command on the active controller, and check for an "S" beside the unit to confirm that the configuration for the unit you are replacing is static.
  2. If the configuration is not static, enter the write memory command to change all dynamic configurations to static. A static configuration remains after the unit is removed.
  3. Remove the old stack unit from the stack.
  4. Connect the new unit to the existing stack using the same stacking ports as the old unit.
  5. Enter the stack interactive‐setup command. Select interactive-setup option 2 if the replacement unit is a clean unit. Select interactive-setup option 3 if the replacement unit contains configuration. Stack interactive-setup suggests an ID based on matching the new unit with the static configurations. You can overwrite the suggested ID by entering the ID of the old unit.
    The active controller resets the unit, and it joins the stack.

Replace examples with non-ICX 7750 examples.
In the following example, units 2 and 3 are removed and replaced. Because unit configuration has been saved, once the units are removed, the show stack command displays the state of both units as "reserve." This indicates that provisional configuration is stored for the two units. 

ICX7750-26Q Router# show stack
T=3h45m17.5: alone: standalone, D: dynamic cfg, S: static
ID   Type          Role    Mac Address    Pri State   Comment
1  S ICX7750-26QXG active  cc4e.2438.7280 128 local   Ready
2  S ICX7750-48XGF member  0000.0000.0000   0 reserve
3  S ICX7750-26QXG member  0000.0000.0000   0 reserve

    active
     +---+
  2/1| 1 |2/4
     +---+
Current stack management MAC is cc4e.2438.7280

If you connect two clean units matching the physical modules of the units you removed, you can use the stack interactive-setup command. 

ICX7750-26Q Router# stack interactive-setup
You can abort stack interactive-setup at any stage by <ctrl-c>
0: quit
1: change stack unit IDs
2: discover and convert new units (no startup-config flash) to members
3: discover and convert existing/new standalone units to members
2&3 can also find new links and auto-trunk or convert chain(s) to ring.
Please type your selection: 2
Sending probes to ports: u1: 1/2/1 to 1/2/6,
Existing stack: ============================================================
    active
     +---+
  2/1| 1 |2/4
     +---+


Horizontal bars link to discovered units. Vertical bars link to stack units.


Chain #0: ==================================================================
#1: icx7750-48-xgf-port-management 609c.9f7f.9400
#2: icx7750-20-qxg-port-management 748e.f8f9.6300

     1/2/1        1/2/4
      ||           ||
      ||           ||
      2/1          2/1
     +---+        +---+
     |#1 |2/4==2/4|#2 |
     +---+        +---+

Discovered 1 chain/ring
Chain #0: Do you want to select this chain? (enter 'y' or 'n'): y
#1: icx7750-48-xgf-port 609c.9f7f.9400, type an ID (No: 0, default: 2):
#2: icx7750-20-qxg-port 748e.f8f9.6300, type an ID (No: 0, default: 3):

You selected 2 unit(s): #1: ID=2, #2: ID=3,

Links U1--U2, #=3: 2/1--2/1 2/2--2/2 2/3--2/3
Links U2--U3, #=3: 2/4--2/4 2/5--2/5 2/6--2/6
Links U3--U1, #=3: 2/1--2/4 2/2--2/5 2/3--2/6

                   #1           #2
    +---+        +---+        +---+
=2/4| 1 |2/1==2/1| 2 |2/4==2/4| 3 |2/1=
|   +---+        +---+        +---+   |
|                                     |
|-------------------------------------|
Proceeding will produce the above topology. Do you accept it? (enter 'y' or 'n'): y
stack interactive-setup discovers 2 unit(s) and sends stack-port/trunk to chain 0:
#1 609c.9f7f.9400 U2, D0: 2/1 to 2/3, D1: 2/4 to 2/6
#2 748e.f8f9.6300 U3, D0: 2/1 to 2/3, D1: 2/4 to 2/6

ICX7750-26Q Router#
T=3h49m1.5: Election, was active, no change, ID=1, pri=128, 2U(1-2), A=u1, nbr#=1 0, reason: u2: port-up, ,
Detect stack unit 2 has different startup config flash, will synchronize it
Detect stack unit 2 has different ssh rsahost key, will synchronize it
T:3h48m43.9: Done hot swap: active controller u1 sets u2 to Ready.
T=3h48m45.4: Synchronize startup config to u2
Flash Memory Write (8192 bytes per dot)
.
Write startup-config done.
Stack unit 2 Power supply 1 is up
Stack unit 2 Power supply 2 is not present
SSH RSA Host Key erase request sent to specified stack member(s)...
T=3h48m52.4: Synchronize ssh rsa host key to u2
T=3h49m22.3: Election, was active, no change, ID=1, pri=128, 2U(1-2), A=u1, nbr#=1 0, reason: u1: port-up, ,
T=3h49m24.9: Election, was active, no change, ID=1, pri=128, 3U(1-3), A=u1, nbr#=1 1, reason: u3: port-up, ,

!!! Temperature is over warning level on stack unit 1 !!!
Detect stack unit 3 has different startup config flash, will synchronize it
Detect stack unit 3 has different ssh rsahost key, will synchronize it
T:3h49m7.9: Done hot swap: active controller u1 sets u3 to Ready.
T=3h49m7.9: Synchronize startup config to u3
Flash Memory Write (8192 bytes per dot)
.
Write startup-config done.
T=3h49m31.3: Election, was active, no change, ID=1, pri=128, 3U(1-3), A=u1, nbr#=1 1, reason: u2: port-up, ,
Stack unit 3 Power supply 1 is up
Stack unit 3 Power supply 2 is down
T=3h49m35.5: Election, was active, no change, ID=1, pri=128, 3U(1-3), A=u1, nbr#=2 2, reason: u3: port-up, ,
SSH RSA Host Key erase request sent to specified stack member(s)...
T=3h49m16.7: Synchronize ssh rsa host key to u3

ICX7750-26Q Router#

When the interactive-setup process is complete, output for the show stack command confirms that the configuration is the same. The provisional configuration has been applied to the two replacement units, 2 and 3, and the state has changed to "remote" for both units. 

ICX7750-26Q Router# show stack
T=3h49m27.4: alone: standalone, D: dynamic cfg, S: static
ID   Type          Role    Mac Address    Pri State   Comment
1  S ICX7750-20QXG active  cc4e.2438.7280 128 local   Ready
2  S ICX7750-48XGF member  609c.9f7f.9400   0 remote  Ready
3  S ICX7750-20QXG member  748e.f8f9.6300   0 remote  Ready

    active
    +---+        +---+        +---+
=2/1| 1 |2/4==2/1| 3 |2/4==2/4| 2 |2/1=
|   +---+        +---+        +---+   |
|                                     |
|-------------------------------------|
There is no standby. Will assign a standby in 47 sec

Current stack management MAC is cc4e.2438.7280
Parent topic: Stack Unit Replacement